Cultivation

Harvest and Post-Harvest

The main problem encountered in chicozapote fruit production is in harvest and post-harvest handling. Fruits must be harvested selectively, since all of the fruits on a tree do not ripen at the same time. The most reliable method of testing the ripeness of the fruits is to examine the color of the skin before and after scratching its surface (Patel and Katrodia 1994). It is difficult to harvest chicozapote fruits by hand, due to the height of the trees and the presence of stinging wasps and ants on the fruits in some areas. Therefore, harvesting is more efficient if a mechanical apparatus is used (Abdul-Karim 1988). After harvest, the fruit ripens quickly and becomes overripe in 10-14 days (Morton 1987, Rao and Chundawat 1989). This is a particular problem for chicozapote, since the fruit is mainly consumed in tropical areas, with limited refrigeration. Many studies have been conducted on devising treatments of chemicals and temperature that extend the shelf life of this fruit. Banik et al. (1988) extended the shelf life to 18 days by storing the fruit in plastic bags with permanganate-silica gel at 10-12? C. Broughton and Wong (1979) achieved the same results by storing at 20? C with ethylene removed and 5-10% CO₂ added. Suryanarayana and Goud (1984) used Ethrel to make the fruit ripen more uniformly, and Brown and Wong (1987) used propylene gas to control the ripening rate. By treating pre-ripened fruits with GA, kinetin and silver nitrate, Gautam and Chundawat (1990) were able to extend shelf life and increase mature fruit quality. The best results, however, were achieved by Mohamed et al. (1996). They found that sealing the fruits in low-density polyethylene film (LDPE) and storing them at 10? C extended the shelf life to six weeks, although fruit quality peaked at four weeks.